Posted
by
timothy
on Thursday September 22, 2011 @08:46AM
from the faster-better dept.

Mark.JUK writes "Telecommunications giant Alcatel-Lucent has today become the first-to-market with VDSL2 Vectoring technology which, it claims, will push the top broadband internet access speeds of existing copper telephone lines over 100Mbps and without needing to bond multiple lines together. Vectoring is essentially a 'noise cancellation' method (similar, in principal, to the technology found in some headphones) that works to cancel out background noise / interference (i.e. crosstalk) and can thus boost performance and reach (coverage) by between 25% and 100%."

Look here boy, my mom never paid for internet. I've always paid for it myself, starting in 1984 or 1985 (don't remember, it's been a while). Latency and bandwidth with the 1200 baud modem were quite adequate for Trade Wars (on a BBS, not many internet games then), I'll have you know.

Judging from the fact that low latency connections aren't available here, I'd have to suggest that it isn't selling. Whether or not it would is another question.

OTOH, we don't have bandwidth over 6mbps available here at all, so perhaps it's just greed and incompetence. Either way, I'd be more than happy to deal with the latency if I could get 100mbps of bandwidth.

Go to dslreports.com and see - the cable provider forums are constantly filled with "high ping" and "lag spiking" complaints. Of course, they refuse to try DSL because their 15/1 connection outclasses the 3/.5 max that they can get via DSL. There are those who use both - DSL for gaming (constant latency), cable for fast downloads.

Go to dslreports.com and see - the cable provider forums are constantly filled with "high ping" and "lag spiking" complaints. Of course, they refuse to try DSL because their 15/1 connection outclasses the 3/.5 max that they can get via DSL.

Maybe that's not the cause at all, and it's because the only DSL provider in their area is a shitty telecom company like Qwest that has horrible service, constant outages, and when they used to have

Then why does anyone have high-speed internet connections? You can get far, far, far more bandwidth with the USPS than you can from any network connection. Of course, the latency is terrible, but you said that it isn't important.

Maybe, I doubt it though. FEC processing on optical signals adds less than a millisecond (I think the numbers I've seen are around 100 microseconds on both ends).
I'm not saying that what they are doing is anything like FEC, but the magic of ASICs can make hard math happen really quickly.

100us sounds a bit high actually. When I run a high-resolution ping on my home network, it claims 0.01ms pings from my computer to my wife's through my Netgear 3700 home router. That right there is only 10us. So, from the time an application instructs the OS to ping a computer to the time the other computer receives the packet, is about 10 millionths of a second, on home-grade equipment.

I believe there is a range and 100usec is the high end, I was being generous. I think I've seen as low as 7usec with slower 2.5 gbps lines using normal FEC (not higher bitrate Enhanced FEC). I'd have to dig through operations manuals to confirm.
This is on optical transport equipment that costs as much as a house, not consumer grade routers which aren't going to have FEC at all.

Just in case... I wasn't trying to say you were wrong, but I found it strange to have that much of a latency difference between my copper networking and a high speed fiber link. The 7us range sound quite fast for a bunch of error checking/correction.

No, not velocity factor but rather the problem of copper POTS having crappy channel characteristics and bandwidth, which means that you have to do heavier and heavier signal processing to squeeze ever more diminishing bitrate improvements out of them. And this signal processing takes time, i.e. adds latency, there's no way around that.
Case in point; pinging from work to home (250 miles, 10 hops) is on the order of 25 ms. That's with fibre all the way into my basement. (50 Mbps up/down for ca $35/mo inc. I

Good point about signal processing. For my home modem, with 11000 feet of copper (long enough to limit my bandwidth), there is indeed a high ping time of 41-45 ms. But that ping is not to the DSLAM in Albany, California. It's to the ATM call termination in Pleasanton, a good deal farther away. I can't really tell how much of the problem is the modem and DSLAM, and how much is elsewhere in ATT's network.

Yes, well it's been a few years since I worked for the wireline division at Ericsson...:-) but as long as it's ATM transport I think that buffer bloat won't be much of a problem at least. Since ATM is basically a (half-assed compromise of a) telecoms standard it doesn't allow for much buffering, as that would hurt call quality. It should be low latency end-to-end. If you know that you're only going to forward IP, then you could start adding more buffering, but I don't know if that's routinely done (and I d

2/3 of the speed of light (in vacuum) is actually about 200000 km/sec. Otherwise the parent poster is correct, though. There is no big difference between the speed of signal propagation in fiber vs copper.

Copper is mainly used for last mile delivery not for backhaul. The majority of latency issues which come into play only if you're really a hardcore gamer are to do with routing and switching. Fibre does not fix this problem, actually it may make it worse as routers are purchased which provide more bandwidth with bigger buffers which further contribute to a the bufferbloat phenomenon which affects and degrades routing.

Furthermore your typical ADSL connection to a local game server is 20-30ms. Unless you're the type of gamer who makes their primary career from p4wning n00bs, reducing this figure by 5ms isn't going to provide you with much of an advance. Not into games? What else is there? About the only other really low latency service (and by this I mean service where 20ms becomes significant) is supercomputing, and for grid projects likely to use home internet connections and consumer hardware this isn't an issue.

So my question back to you: Why is it a problem? What are you hoping to fix?

Yeah yeah, lord it over me why don't you =p
I live in the northern ass end of Canada and pay $129/month for my internet connection(100gb/month $13/gb for additional usage), which promised 25mbps while providing just shy of two, and leaving me with a ping of about 90-150 to a typical server in southern Canada or the north end of the States. I pray this is not the sign of things to come, but we both know Bell, Rogers and co will charge these prices with a grin elsewhere if consumers can be convinced to pay.

I live in a city in the UK which supposedly has some of the fastest broadband in the country. Yet, i rarely touch 1mbps (usually between 500-700k). This costs me £20 per month. It is uncapped, but I dont know why I bother paying extra for that, not like I could possibly max out my allowance anyway.

At least you dont have to live around a bunch of people who are getting 20-50mb and rubbing it in your face.

This means TFA is advertising download speeds of up to 12.5MB/s, not 100MB/s.

And with latency, network congestion, and signal quality that means an internet user with a 50GB cap will blow through their entire months allotment in around 90 minutes. With the cost of overages being so absurdly don't be shocked if you start seeing the telco's and cableco's be super eager to spend the money to get this into homes quickly.

Its a veritable cash cow waiting to happen, especially as hi-def streaming sites get more a

You playing video over your remote desktop? It is still largely bandwidth intensive. I have not problem on ADSL2 doing a remote desktop session at high resolutions. I had no problem on my original ADSL session on a service where I was lucky to get 70ms. There is very little in a remote desktop session that requires reduced latency. If you're the type to complain about your mouse cursor not moving damn bloody instantly, then maybe remote desktop isn't the solution you seek, or pick a different protocol.

About the only other really low latency service (and by this I mean service where 20ms becomes significant) is supercomputing

Well, there's program trading. There was a story a couple of days ago of a new $300M transatlantic cable being laid whose sole purpose is to reduce transit times (latency) by 6ms from the current 60ms. The consumers for this are hedge funds/etc doing program trading - the article said that a large hedge fund might make $100M/yr extra from a 1ms data advantage.

True, but this is not directed at them. The average home trader can't keep up with the trading floor anyway. 99% of brokerage services have quotes delayed by 15 minutes, the 1% which don't cost so much that you should have a direct tap into the local stock exchange anyway.

Another reply to the parents post was right. Fibre already covers the low latency market, so it's not like there's no other option. But my reply in general was that bandwidth is for average home user the biggest problem and I for one look

Unfortunately game servers are typically not that "local", at least for most of the people on it. I usually find around 90+ms are as far down as they go for me anyway. But as long as it doesn't get too far past 100ms it's hardly even noticeable.

Latency in browsing is not something I consider latency as even with a poorly configured DNS server the latency is often small compared to the time it takes to load the page.

Think direct connections, VoIP and games come to mind as latency sensitive with consumers, and once a direct connection is established routing definitely takes up the most of it unless you're playing on a server half a world away.

I suspect most latency when using copper comes from error correction. You could try having your ISP lower/zero your interleave value.. [wikipedia.org]
That can shave off 10-20ms, but it requires that wires aren't crap..

As others have said at least in the case of DSL the latency doesn't come from the copper line itself. It comes from the signal processing used to squeeze relatively huge amounts of data down a line designed for analog voice.

In particular when using forward error correction techniques (which are pretty much essential when you are running close to the limit of a channels capacity) it often makes sense to interleave frames. That way if there is a burst of noise it's impact will be spread across multiple frames

Say what? Copper itself doesn't have inherently more latency than fibre (in fact, the propagation speed of a signal in copper is slightly faster than light in fibre). I suspect you are referring to frame interleaving commonly used on xDSL connections. Which can be turned off. My ISP allows you to change this setting from the toolbox on their website... first hop latency reduces from ~20 ms to ~9 ms if I do so. Once you're past the first hop the additional latency to the destination will obviously be the sa

Latency isn't a copper issue... Between 100Mbps copper and 100Mbps fiber you should get the same latency.Now if you compare a Gbps PON (fiber) access with a 10Mbps ADSL, then of course the ADSL will have much higher latency.I have a 12Mbps/1,2Mbps ADSL2+ link and I can ping the ISP's router with less than 10ms delay.

And there are those of us that would be grateful to get 25mbps, around here the ISP only offers 6mbps tops if you go with cable or 5mbps with DSL. And that's assuming that you're in a neighborhood where they care about providing a halfway decent connections, some of the neighborhoods top out at 1.5mbps.

I'm in Sweden, the ISP's here have invested slightly more in the backbone or whatever the cause may be. I feel I need to add though that I mistyped, 25mb/s is my maximum theoretical speed. In reality, it goes up to about 12. Although, I don't really need more, but wouldn't mind it.
Anyway, I'm aware of the situation many people find themselves in (mainly in the US, Australia and NZ it would seem). It's a good thing they continue developing connection over copper though. If they can't be arsed to fix the co

That may be so, but in my case they have screwed up too many times in the past (going back 15 years or so) to ever get my business again. It's not about how good their internet service is, it's about my feelings for them as a company and how I have been treated by said company.

Comcast is capped and when they had my business they managed to be out several hours every single afternoon. Even if they have fixed their service, they're still capped and barely any faster than DSL. On top of which, I'd be sharing bandwidth going to the ISP.

I get 34mbps down, about 2mbps up. Pulled over 250gbs last month. No cap, and its fast enough for me. I saturate every server i try to download from. I'm glad everything done by the big distros is on torrent. It's nice downloading a distro in a few min.

Just like DSL and FIOS.DSL: Dedicated up to the dslamFIOS: shared at every point. --Best not because of best bandwidth, but fiber generally has fewer issues and is easier to troubleshoot. Much more reliableDOCSIS: hybrid of shared and not shared. Implementation dependent.

Yeah, this is all well and good if you live next door to the CO or in a city with new copper. Anyone living in the vast majority of 'older' cities and towns on the east coast is dealing with copper that was installed before the 1960's and has no shot at this kind of speed.

Don't worry, it is actually cheaper to trench fiber now than copper, so you will see this happening if you haven't already. I can't speak for the States, but new subdivisions in Western Canada actually have fiber being run to them from day one instead of copper lines. Profit motive is a great thing, and the international demand for copper has made this a reality. What you will not see is fiber being rolled out to existing neighborhoods - it is usually much cheaper to upgrade the neighborhood's cabinet to pr

Bell's VDSL2 rollout also includes installing remotes in the basements of MDUs (apartment/condo buildings) to serve them and surrounding buildings. I'm 147 feet from my VDSL2 DSLAM.

It's an easy win; you install a small RDSLAM in the basement and run some fibre to it, and suddenly you can offer VDSL2 internet and HD IPTV to 250 new potential customers. And hey, if the neighbouring buildings are close enough, multiply that by a few times.

This. TELUS does exactly the same in the West. You don't NEED fiber to the home when your DSLAM is that close, and in most cases you can even avoid laying new copper. The technology just gets a bad rap when incompetent ISPs try to sell you xDSL service through a shoddy local loop, and then refuse to roll a truck to fix it.

My 100Mbps last mile copper line here in Canada (Shaw Cable - been active for the past half year) has a 500GB/mo cap. There's talk of a 250Mbps with 1TB/mo cap (or unlimited) options coming out later this year. The price isn't exorbitant too, too much for college kids, but $99/mo with digital cable isn't *that* bad.

It's not all horrible up here.

(And yes, Teksavvy should have the right to offer the same Internet service without cable on the same copper at a fraction of that price)

Heh:) I have 15 (now 25, I think?) Mbps cable through TekSavvy with no cap, running on Rogers' lines. I've heard good things about Shaw's cable offerings out West, but there's zero chance we'll get anything like that from Rogers in Ontario anyway.

standard service is still around 50$, 8Mb down/1Mb up, with a ridiculous 50GB limit. And with only 2 ISPs, it's not going to change that much (almost all the other ISPs are resellers, and are subject to the same limits, thanks to CRTC)

And since they also own TV stations and are tv providers, that's not abo

Verizon uses VDSL as part of their FIOS service in apartment buildings if they can't get access to run fiber to the apartment. This usualy limits bandwidth to about 30Mb downstram and 4 or 5 Mb upstream.If they switch to VDSL2 then I may finally get the full 35/35 speeds I'm paying for.

So what about upload speed? Really, that is the achilles heel of all of these technologies. Also how many people are going to live in the zone that gets 100mbps or will it be like where I live, suburban area Perth with a cable run 4km from the exchange (don't mind that the exchange is abount 1.5k away via the road) and getting ADSL1 speeds, but paying for ADSL2+ (which is actually cheaper as it's not provided by the semi privatised monopoly called Telstra).

Upload speeds on VDSL2 aren't automatically fixed like they are on ADSL. Different VDSL2 profiles use different splits. Personally, I've got 25 megs down, 7 megs up, and I've bonded two of those to get 50 megs down, 14 megs up.

The distance issue just requires them to push the remote DSLAMs closer to the customers. In my case, Bell Canada has installed the VDSL2 RDSLAM in the basement of my building. I'm 2400m from the CO, but only 45m from the closest DSLAM.

There is an important distinction to make when looking at upload speeds for any access technology. First of all, there is your train rate - this is the rate you are getting to the local cabinet. ADSL offered very little in terms of upload train rates, but VDSL2 is much more generous. For example, my VDSL2 at home is 60 Mbps/25 Mbps. Now, you also need to consider your committed rate, which is usually determined by your Layer 3 gateway inside the service provider network. My committed rate, right now, is act

The backhauls are uniformly symmetric links, as are all the other links in the network aside from the ADSL/VDSL. The upstream bandwidth in the network is just going to waste. It's just the dog-in-the manger attitude of the phone companies that is throttling the rates. Even if it would cost them literally nothing, they see no reason to give it to you unless you pay more.

VDSL and VDSL2 don't have a bias for download (or upload) bandwidth. Your carrier can choose anything from fully symmetric to heavily asymmetric, but the technology itself doesn't care. Bandwidth is not arbitrarily pre-allocated like with ADSL.

All these wonderful high-speed Internet connections do us no good if the telcos refuse to deploy them. I live just a few miles out from DC, and I can't get any broadband because Verizon refuses to install it.

I would be interested to know if the technology to boost bandwidth on copper might also help push bandwidth out further. A lot of us rural folk still don't have a lot of choices when it comes to broadband and all of them are expensive.

Not really, there hasn't been any real advancements in long-distance DSL since ADSL2's annex L (Re-ADSL2), which cranked up the power a bit to extend the range.

ADSL, ADSL2, and VDSL2 all behave about the same after a certain point. VDSL2 can do 250 mbps symmetrical at source, but after 1600m, it performs the same as ADSL2+, and eventually, the same as ADSL. All these newer DSL standards are really doing is crank up how much spectrum is used, enabling faster speeds at the distances short enough to be able to

I live in a distressingly urban area, but am still too far from the Qwest CO/site to get ?DSL* faster than like 5Mb/s down. A technology being available doesn't mean that it will be deployed in any useful fashion.

Conversely on that broadband cable line already coming to your house, each 6MHz channel can support a downstream rate of 42.88Mb/sec using QAM256 (with some of this as overhead). Devoting that entirely to "Internets", the usable frequency range of that cable (typically) is from ~54MHz to 750MHz which represents 116 channels. 116*42.88 = 4974Mb/sec, or ~5Gb/sec of useful data in one direction. Cut that in half, and allowing for upstream inefficiencies (Q

VDSL2 only gives good speed if you have short high quality loops to a cabinet. You end up with lots of cabinets attached to a fiber network. All the effort to achieve this is better spent extending the fiber the last little bit to the building which allows for fewer and better placed cabinets. As a result VDSL2 is only good for things like apartment buildings with no provision to add fiber. It is more or less a stillborn technology.

On one hand, you are correct - you need a superb loop to a nearby cabinet, and these cabinets must be attached to a fiber network. On the other hand, trenching new fiber to an existing home is prohibitively expensive, and then you need to replace the entire cabinet anyway to support fiber subscribers instead of copper! There are a few exceptions to this, such as aerial fiber, but this is rarely an option. If installing a new cabinet is not an option, an ISP will usually opt for wireless. Not entirely ideal,

From the estimates I saw for the UK FTTC/FTTP rollout, doing full FTTP everywhere was estimated at about five times as expensive as just running fibre to the street cabinets and using VDSL2 from there.